Installing and configuring Django on a “combat” server with CentOS 5
I do on Django the Encyclopedia of programming languages about which I already wrote on Habré . During the work of the site it turned out that we need our own dedicated server for greater performance and stability. So far, I have taken a cheap server with a 1.8 GHz processor and 512 MB of memory.
In this article I will discuss installing and configuring Django on this server with mod_python for Apache, with memcached and lighttpd caching for static files.
So, we have a freshly installed CentOS 5 and a desire to host a site on Django (or several sites).
')
What do you need to install for this?
All steps, apart from installing Django itself, are optional (for example, you can use Django with fcgi instead of mod_python and PostgreSQL or another DBMS instead of MySQL), but steps 1-3 are what you are likely to use and 4-5 for increase productivity.
The article is mainly CentOS-oriented, but to a certain extent suitable for other Linux distributions.
Security note: since this is a freshly installed system, I’m not afraid to break something already working, so I can work as root. But it is better, of course, to work under the rights of an unprivileged user, and use “sudo” for commands that require administrative privileges.
Let's start.
Django proper
In most cases, it is worthwhile to install the latest svn version of Django, not “release”. At the moment, the “official release” is too outdated and lacks many useful features (for example, unicode support and auto-escape).
To install, enter on the command line
Also installing Django with svn is discussed in the official Django documentation .
After installing Django, you need to copy the files of your project to the server (via svn or simply copying via ssh or ftp; you should also add an individual user to the system who will own these files) and dump the database, and then adjust the database settings in the file .py (meaning that MySQL is already installed and configured, the database and the user are created, all data is in place - these things are far beyond the scope of this article).
Now try running the Django development server from the project directory.
The version of MySQL-python in the CentOS distribution is too old to run a fresh svn version of Django, so you need to compile it from source.
MySQL-python
To build MySQL-python, gcc, python-devel and mysql-devel packages will be needed.
Try running python manage.py runserver 127.0.0.1:8000 again and see if there are any errors. For example, I use ImageField in my project, so I had to additionally install the Python Imaging Library (yum install python-imaging).
If there are no errors, you should change 127.0.0.1 in the runserver command to the IP address of your server and test the operation of the site using a browser, but you need to open port 8000 in CentOS firewall or temporarily disable the firewall (or you can just turn off Apache and launch Django development server on port 80).
If there are no errors, then it's time to turn off the Django development server and configure Apache.
mod_python
Configuring Apache with mod_python to work with Django is simple: just follow the instructions from the official Django documentation .
One note: since MySQL-python is installed as an egg package, it is important to create a temporary directory (set 777 permissions on it) for caching .egg and point to it in httpd.conf
memcached
Enabling caching of memcached is very important for increasing performance. Unfortunately, memcached is not in the CentOS repositories, so again you have to compile from source. This section of the article is based in part on this HOWTO .
First you need to install libevent:
To get even more performance, you need to give static files not with Apache, but with a less resource-intensive server - lighhtpd.
lighttpd
Again, install from source.
Also change the server.document-root to “/ var / www / html /” and create a symbolic link “/var/www/html/media.yourdomain.com/” pointing to the media directory of your project.
And at the end some more performance tips:
In this article I will discuss installing and configuring Django on this server with mod_python for Apache, with memcached and lighttpd caching for static files.
So, we have a freshly installed CentOS 5 and a desire to host a site on Django (or several sites).
')
What do you need to install for this?
- Django proper
- MySQL-python
- mod_python
- memcached
- lighttpd
All steps, apart from installing Django itself, are optional (for example, you can use Django with fcgi instead of mod_python and PostgreSQL or another DBMS instead of MySQL), but steps 1-3 are what you are likely to use and 4-5 for increase productivity.
The article is mainly CentOS-oriented, but to a certain extent suitable for other Linux distributions.
Security note: since this is a freshly installed system, I’m not afraid to break something already working, so I can work as root. But it is better, of course, to work under the rights of an unprivileged user, and use “sudo” for commands that require administrative privileges.
Let's start.
Django proper
In most cases, it is worthwhile to install the latest svn version of Django, not “release”. At the moment, the “official release” is too outdated and lacks many useful features (for example, unicode support and auto-escape).
To install, enter on the command line
svn co http://code.djangoproject.com/svn/django/trunk/ django-trunkBut first you need to install svn
yum install subversionAfter receiving all the files from svn, you need to make a symbolic link to Django in the site-packages directory for Python:
ln -s `pwd` / django-trunk / django /usr/lib/python2.4/site-packages/djangoMake sure that all the parent directories in the django directory have the correct permissions (read access for the httpd user, usually chmod 755).
Also installing Django with svn is discussed in the official Django documentation .
After installing Django, you need to copy the files of your project to the server (via svn or simply copying via ssh or ftp; you should also add an individual user to the system who will own these files) and dump the database, and then adjust the database settings in the file .py (meaning that MySQL is already installed and configured, the database and the user are created, all data is in place - these things are far beyond the scope of this article).
Now try running the Django development server from the project directory.
python manage.py runserver 127.0.0.1:8000On CentOS 5 there will be an error message “Error loading MySQLdb module”.
The version of MySQL-python in the CentOS distribution is too old to run a fresh svn version of Django, so you need to compile it from source.
MySQL-python
cd / usr / local / src wget http://garr.dl.sourceforge.net/sourceforge/mysql-python/MySQL-python-1.2.2.tar.gz tar xvzf MySQL-python-1.2.2.tar.gz cd mysql-python-1.2.2
To build MySQL-python, gcc, python-devel and mysql-devel packages will be needed.
yum install gcc yum install python-devel yum install mysql-devel cd /usr/local/src/MySQL-python-1.2.2 python setup.py build python setup.py installDone, MySQL-python is installed as an .egg file in the site-packages directory.
Try running python manage.py runserver 127.0.0.1:8000 again and see if there are any errors. For example, I use ImageField in my project, so I had to additionally install the Python Imaging Library (yum install python-imaging).
If there are no errors, you should change 127.0.0.1 in the runserver command to the IP address of your server and test the operation of the site using a browser, but you need to open port 8000 in CentOS firewall or temporarily disable the firewall (or you can just turn off Apache and launch Django development server on port 80).
If there are no errors, then it's time to turn off the Django development server and configure Apache.
mod_python
Configuring Apache with mod_python to work with Django is simple: just follow the instructions from the official Django documentation .
One note: since MySQL-python is installed as an egg package, it is important to create a temporary directory (set 777 permissions on it) for caching .egg and point to it in httpd.conf
<Location "/">
...
SetEnv PYTHON_EGG_CACHE / var / tmp / egg
</ Location>
And do not forget to restart Apache after changing httpd.conf:/etc/init.d/httpd restartNow the site should work through Apache on the usual http-port. Check out the browser.
memcached
Enabling caching of memcached is very important for increasing performance. Unfortunately, memcached is not in the CentOS repositories, so again you have to compile from source. This section of the article is based in part on this HOWTO .
First you need to install libevent:
cd / usr / local / src wget http://monkey.org/~provos/libevent-1.4.2-rc.tar.gz tar xvzf libevent-1.4.2-rc.tar.gz cd libevent-1.4.2-rc ./configure make make install vi /etc/ld.so.conf.d/libevent.conf ## add a line: / usr / local / lib / ldconfig -vThen memcached itself:
cd / usr / local / src wget http://danga.com/memcached/dist/memcached-1.2.5.tar.gz tar zxvf memcached-1.2.5.tar.gz cd memcached-1.2.5 ./configure make make install cp scripts / memcached.sysv /etc/init.d/memcached ln / usr / local / bin / memcached / usr / bin / memcached /etc/init.d/memcached start chkconfig memcached onFinally, you need to install libmemcache and cmemcache (python extension for libmemcache):
cd / usr / local / src / wget http://people.freebsd.org/~seanc/libmemcache/libmemcache-1.4.0.rc2.tar.bz2 bunzip2 libmemcache-1.4.0.rc2.tar.bz2 tar xf libmemcache-1.4.0.rc2.tar cd libmemcache-1.4.0.rc2 ./configure make make install cd / usr / local / src / wget http://gijsbert.org/downloads/cmemcache/cmemcache-0.91.tar.bz2 bunzip2 cmemcache-0.91.tar.bz2 tar xf cmemcache-0.91.tar cd cmemcache-0.91 python setup.py installEnable memcached caching in your project’s settings.py
CACHE_BACKEND = 'memcached: //127.0.0.1: 11211 /'(if you need more information, look in the official Django documentation ) and restart Apache.
To get even more performance, you need to give static files not with Apache, but with a less resource-intensive server - lighhtpd.
lighttpd
Again, install from source.
cd / usr / local / src wget http://www.lighttpd.net/download/lighttpd-1.4.19.tar.bz2 bunzip2 lighttpd-1.4.19.tar.bz2 tar xf lighttpd-1.4.19.tar cd lighttpd-1.4.19 yum install glib2-devel openssl-devel pcre-devel bzip2-devel gzip-devel ./configure make make install cp doc / rc.lighttpd.redhat /etc/init.d/lighttpd chkconfig lighttpd on mkdir / etc / lighttpd cp doc / lighttpd.conf / etc / lighttpd /And now you need to configure Apache and lighttpd so that the static files are given to lighttpd (on port 80), and the rest of the requests are serviced by Apache on port 81 (thanks to nolancaudill.com for this solution):
- Configure Apache for port 81: find
Listen 80 and replace with Listen 127.0.0.1:81. Also, do not forget to change the port number in all VirtualHost directives. Restart Apache. - Edit /etc/lighttpd/lighttpd.conf. Remove comments from the 'mod_alias' and 'mod_proxy' modules and add lines (correct for your needs):
$ Http ["host"] == "yourdomain.com" { # here we are mapping / media / for admin media # and / static / for the standard media_url alias.url = ( "/ media /" => "/usr/lib/python2.4/site-packages/django/contrib/admin/media/", "/ static /" => "/var/www/html/media.yourdomain.com/", ) $ HTTP ["url"]! ~ "^ / (Static | media) /" { proxy.server = ("" => (("host" => "127.0.0.1", "port" => 81))) } }
Also change the server.document-root to “/ var / www / html /” and create a symbolic link “/var/www/html/media.yourdomain.com/” pointing to the media directory of your project.
- Create a directory for lighttpd log files:
mkdir / var / log / lighttpd /
- Another small edit in /etc/init.d/lighttpd: change it from / usr / sbin / lighttpd to / usr / local / sbin / lighttpd. Run lighttpd:
/etc/init.d/lighttpd start
And at the end some more performance tips:
- disable all unused services
configure MySQL parameters (for example, you can use the tuning-primer.sh script)
turn off KeepAlive in httpd.conf
more tips from Jacob Kaplan-Moss (one of the creators of Django)
If interested, in the same vein, I plan to continue writing on the My Django blog.
Source: https://habr.com/ru/post/23895/
All Articles